[SERVER-30232] delete command on mongos can return a negative count of deleted documents - MongoDB

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Create a collection named "test" with 2,147,483,648 documents. That's one more than the largest possible positive number that can be represented with a 32 bit signed integer.

Run the following command:

db.runCommand({ delete : "test", deletes : [ { q : {}, limit : 0 } ] })

The expected result is:

{ "ok" : 1, "n" : 2147483648 }

The actual result is:

{ "ok" : 1, "n" : -2147483648 }
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Create a collection named "test" with 2,147,483,648 documents. That's one more than the largest possible positive number that can be represented with a 32 bit signed integer. Run the following command: db.runCommand({ delete : "test", deletes : [ { q : {}, limit : 0 } ] }) The expected result is: { "ok" : 1, "n" : 2147483648 } The actual result is: { "ok" : 1, "n" : -2147483648 }

When a very large number of documents matches the query the count of deleted documents can overflow and become negative.

I have reproduced this with 3.2.10. It works correctly in 3.4.6.

This ticket might be a duplicate, but I couldn't find a ticket for this.

related to

CSHARP-2017 DeleteMany().DeletedCount overflow